My clearance lights stopped working on me while i had the mh out last time, I was wondering if anyone else has had this problem?? I tested all the wires coming out of the switch and I had a white wire which had no power so I thought maybe that was it, so i jumped a power wire to it and still no lights... does anyone know where the wires for them run or what colors.... or anything else to look for. Its front and back top clearance lights and the light over the fenders.

Have you checked the fuses. The parking lights will have a separate fuse.

If you truck chassis is a GM product you may have to look at the head light switch. GM does not use wiring large enough for any additional lighting other than what is on their original chassis. Any additional load on the parking light circuit from additional lights on the truck or from a towed car will cause the wiring to melt usually right at the back of the head light switch. The problem can also be in the head light switch as the copper foil on the printed circuit boards sometime lift off the board from the added heat.

A couple of times I've run across a vehicle with all running lights out, and it turned out the bulbs were all blown. The culprit turned out to be a bad voltage regulator on one, and a bad chassis ground on the other.

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Terry

I checked all wires are actually in the switch, none have fallen out. I will check around the icc switch and see if i can find anything there. I have checked all fuses that are in the fuse panel. I doubt there would a fuse a lone somewhere for these?

On the chance that it might be a Chassis ground problem I would get a long wire and attach one end directly to the battery ground and the other to your test light. With this I would then work my way through the circuit starting with the feed side of the switch, the output side of the switch and so on. If you get to a point that you can not follow the wiring any further I would open one of the lights and test both sides of the fixture. If you have voltage there it is a chassis ground problem. If you do not have power there but did have it on the output side of the switch it is most likely a broken wire or open connector.

Well I found the problem, I have power coming into the icc switch, but no power coming out. Can I simply wire my single brown wire(which runs to the lights) in with the 2 hot wires coming in?? I touched them for a second and had clearance lights. I don't see where that should be a problem since the icc switch is simply for convienence and doesnt actually have an electrical purpose correct?? Is this how everyone else fixed theirs?

If the load originally went through the ICC switch you know that the circuit feeding that switch is fused for this load. Given that I would wire a relay across the input circuit of the ICC switch and the wire you know feeds the lights. Then I would connect one side of the coil of the relay to the head light switch output and the other to ground. This would control your marker lights when ever the head lights are on. A 30 amp auto relay is about $7.00 a lot less that a new ICC switch.

If you wanted any other control over the markers you could add a toggle switch also powering the coil of the relay. This would give you manual control of the markers, as when parked with head lights off.

My clearance lights stopped working on me while i had the mh out last time, I was wondering if anyone else has had this problem??...

There is a huge amount of amperage running through both the ignition switch and the light switch....either or both of these important switches could be the source of a variety of problems....

I think the ICC switch is somehow connected to the ignition switch (maybe via a solenoid?), but am not 100% for certain. Unfortunately, I do not know of ANY publication which documents the internal (Airstream supplied) 12 volt chassis wiring.

Welcome to the never ending world of chasing Vintage MoHo maintenance issues.

Are there only the two wires (in and out) across your ICC switch?

Since you indicate two hot wires coming in the "hot" side may be used as a junction terminal...then again...maybe not.

The power for the clearance lights comes from the parking light power wire at the headlight switch. Airstream used a little cheesy squeez tap to add their clearance light wire to the GM wire. The power then goes up to the ICC Blink switch. This switch is used to blink your clearance lights to say "thank you " to others on the road. The ICC Blink switch is just a normal on, momentary off interupter switch. You can get a new one at Radio Shack.
I had problems with the wire between the headlight switch and the cheesy tap overheating. I just replaced that section of wire (about 3") with a larger guage. I also replaced their tap with a good crimp connector.
Rob

Thanks Rob, that is what I was thinking, the icc was just a normal toggle disruptor. As I drive a tractor trailer and all trucks come with one of these, rather than trying to modify the switch or any of that I simply added a 30amp in line fuse in place of the icc switch. I dont see why that shouldn't work??? Afterall a quick pull and release of the 4 way flashers is quite popular these days anyways.

Wondering if someone could tell me what is the safest way to remove front clearance lights and the housing that they are mounted to. Discovered a leak today up front, and figured I'd get at any possible areas for leaks, from front to back, before finishing up roofing paint.